How it works is the black part are a standard 4 post hoist. They carry the yellow parts with them. You can slide the yellow beams anywhere along the cross beams.
1) mines an early one... probably from the 70's with just Ibeams, I think the later ones have sliding jacks that run down the Ibeams
2) It depends if there is "Ibeam" jacks/rises to allow you to support the car from its body (rather than the axles). I imagine the jacking beams would be in the way, so you would just roll them to the sides. in this case a normal 4poster rolling jack would be better.
3) No, once they are locked in, they stay put. I lower the ramps to a comfortable height to be a work bench/seat once the car is supported.
4) Not at all that I have noticed. It would probably suck if you were used to a clear floor under a 2 post hoist. If you need a clear floor, just drop the ramps down until the are no longer holding supporting the wheels, and leave them up high out of the way :)
If you're removing bodies from chassis and axles from chassis, I'm guessing nothing is going to beat a 2post hoist!

